---
title: "Ruler"
description: "A line that can be used to align layout children inside a [Placeable.PlacementScope]."
type: "class"
---

<div class='type'>Class</div>


<a id='references'></a>

<div class='sourceset sourceset-common'>Common</div>


```kotlin
sealed class Ruler(internal val calculate: (PlacementScope.(Float) -> Float)?)
```


A line that can be used to align layout children inside a `Placeable.PlacementScope`.